TRACING
Start
G
History
Start
G
R
A
T
G
R
R
R
G
O
T
O
A
T
T
O
O
A
A
G
A
G
A
T
R
G
T
R
O
A
G
O
T
G
O
A
O
O
O
A
R
R
T
G
R
T
R
T
A
G